Temperature indicator



M. C. WHITE TEMPERATURE INDICATOR May 19, 1925. A 1,538,418

Filed net l3. 1:5

' Patented May 19, 1925.

. To all whom it may concern.'

UNITED STATES MORRIS C. WHITE, .OF FRANCISCO, CALIFORNIA, ASSIGNOR 0F ONE-FOURTH 'JTOV 1,538,418 PATENT or-F1os.

" ARTHUR o. Tnonrn, or OAKLAND, CALIFORNIA.

TEMPERATURE INDICATOR.

Application led October 13, 1923. Serial No. 668,295.

Be it known that I, Monnis C. WHITE, a citizen of the United States, and a resident of the city and county of San Francisco, State of California, have invented a certain new and useful Temperature Indicator, of which the following is 'a specification.

The invention relates to a temperature in- "dicator adapted to be 'associated with the Vwater cooling system of an internal combustion engine on an automobile, for the purpose of vindicatingv safe and dangerous temperatures of the engine.

An object of the inventlon is to'iprovide a temperature indicating instrument which J is sensitive 'to temperature changes and rugged in construction.

Another lobject of the inventionv is to provide a temperature indicator which operates to display one signal during the eX- istenoe of safetemperatures and to display another signal during the existence of dangerous temperature. f

Another object of the invention is to provide a temperature indicating instrument which is not deleteriously eected by the inversion of the instrument.

' Another object of the invention is to provide improved means for securing the glass disc to the frame.

The invention possesses other advanta- `geous features, some of which, with the regoing, will be set forth at lengthin the following description, where I shall outline in full, that form of my invention which I have selected for illustration in the drawings accompanying and forming' part of the present specification. In said drawings I have shown one form oftemperature indicatorembodying my invention, but it is to be understood that I do not limit Inyvself to such form, since the invention, as

' Figure 3 is .an elevation on an enlarged scale of the operative element ofthe indicator of my invention.

Figure 4 is a perspective view of the sliding flag for indicating safel variations iu temperature.

- The instrument of my invention is particularly'adapted to" be used for indicating the temperature of the water in the cooling system of 'an automobile engine. Indicators for this purpose are usually mounted on the radiator cap, with a temperature sensitive portion of the instrument extending through the cap into thermal contact with. the water in the radiator.

The device of my invention comprises a frame 2, preferably circular in form provided on its lower end with a base 3 having aseat therein for 'the washer 4 which bears against the top of the radiator cap. The frame and base are preferably made of cast Vmetal and embedded in the cast metal is the neck 5 of the chamber 6 which extends downward below'the base. lThe chamber' is provided at the upper portion of its outer face with a screw thread 7 for receiving a nut for clamping the instrument to the radi ator cap. The walls forming the lower portion of the chamber are thin so thatheat is lrapidly conducted therethrough and the chamber contains a small charge of a volatile liquid, such as ether, so that the pressure within the chamber varies with the instrument is inverted, for instance when the radiator cap is removed and this inversion of the instrument would cause the volatile 1i uid to flow from the chamber 6 into the tu e 8, wherein it might be trapped, so that future readings of the instrument would be in error. To revent this condition I provide means or preventing the small amount of volatile liquid in the chamber 6 from entering the tube 8 vwhen the instrument is inverted. `Disposed in. the neck 5 is a nipple 13 which forms a liquid tight joint with the neck. The nipple has a short body in contact with the neck and extends downward into the neck, forming with the wall thereof, an annular chamber in which the liquid collects when the instrument is inverted. This causes the liquid to be retained in the chamber and prevents it from entering the tube. The nipple is provided with a small passageway therethrough to permit vapors to pass between the tube and the chamber, so that the pressure within the tube and chamber is always equal.'

The opening in the frame is closed on opposite sides of the center thereof vby dials 14 and 15 having apertures therein corresponding in position so that light may pass through the instrument. Each dial is pro-v vided with a vertically disposed elongated sight opening 16 arranged adjacent the lower portion of the dial and with a second sight opening 17, preferably circular in shape and disposed above and spaced from the sight o ening 16. These dials seat against shou ders 18 of the frame and may be separately held in place or may be held in place by the 'glass disc or crystals 21 and 22 which form the opposite faces of the instrument. Y vided with outwardly inclined bevelled edges 23 and means are provided for holding these dises in fixed position. Each disc is centered by engagement with the internal periphery of the frame and is held in place by a metallic snap ring 24 which is interposed between the bevelled face of the disc and an overhanging shoulder 25 on the frame. This shoulder 25 comprises one of the walls of a V-shaped groove 26 formed in the inner periphery of the frame, the diameter of the inner edge of the shoulder being substantially equal to the diameter of the disc, so that the disc may be readily inserted. The inclination of the wall 25 is slightly diiierent than the inclination of the bevelled edges 23, the two surfaces approaching each other inward. The snap ring` is interposed between the bevelled edge 23 and the inclined shoulder 25 and securely locks the discl in position. When it is desired to reinovethe disc, the snap ring is removed by any suitableA sharp pointed tool and the disc is then free to be extracted.' This construction eliminates the use of clamping rings for the disc, with the necessary screws for holding the clamping rings in place and greatly improve the appearance of the instrument and at the same time reduces the cost of manufacture.

Arranged within the frame and disposed -rticall' therein is a guide member 31 preferably in the form of a thin ilat strip which is seated at its end in sockets formed in the internal peripheral face of the frane. This guide 31 is preferably arranged to one side of the sight openings 16 and 17. Slid- The glass discs are pro--' ably mounted on the4 slide 31 is a vertically movable flag-'32 preferably formed of green translucent material such as -celluloid. This Hag 32 is mounted in a clip 33 which is free! ly slidable vertically on the guide and as the temperature conditions within the chamber 6 vary, this slide is moved upward and downward occupying varying positions behind the sight opening 16. This flag indicates safe working temperatures of the motor and is readily visible by the driver of the automobile. The clip 33 `is provided with ears 34 through which the guides extend and is provided with an ear 35 through which an actuating lever 36 extends. The actuating lever 36 is pivoted to the frame 2, preferably on the horizontal center line of the frame and is provided on its movable end with 'a curved portion extending through the ear 35 so that the ear will not bind on the lever. Soldered or otherwise suitably secured to the free end 9 of the Bourbon tube is a link 37 Which is provided at its other end with an eye 38 surrounding the lever 36. As the free end of the tube moves the lever 36 is moved about its pivot causing vertical movement of the flag 32. An increase in temperature within the chamber6 causes the flag 32 to move upward along the side opening 16 and as long as this Hag remains in this opening safe tem Jerature conditions exist in the engine.

ounted on the guide 31 above the sight opening 16 is a clip 41 carrying a red flag 42 made of suitable translucent material. This iag is normally supported behind the bridge between the sight opening 16 and 17 so that it is not visible. this position .by a bracket 43 formed on the rear of the dial 14 and being engaged by the projectingl ear 45 of the Hag 42. s the temperature within the chamber 6 increases beyond safe working limits, the clip 33 moves upward and contacts with the clip 41 and moves this clip upward to bring the flag 42 into vision in the aperture 17 thus The flag is supported in indicating the presence of a dangerous tempera-ture in the engine. The flag 32 moves up beyond the limit of the sight opening 16 l so that when the flag 42 is visible the flag 32 is concealed. The instrument is very sensitive and quickly responsive so that upon the existence of a dangerous temperature, the flag 42 is very quickly displayed in the opening 17, causing a red signal to be displayed which impels the attention of the driver and notifies him of the dangerous temperature existing. The instrument thus not only serves as an indication of the temperature, but by displaying a red signal draws the attention o the driver to the existing dangerous conditions.

I claim:

1. A temperature indicating instrument comprising a disc having a `vertically dis- 2. A temperature oindicating instrument comprising a disc having a vertically disposed elongated slot therein, a flag movable vertically along said slot and being visible therethrough, a guide on which said flag is slidably mounted and temperature responsive means for imparting vertical movement to said flag. v

3. A temperature indicating instrument comprising a disc provided with two vertically alined spaced sight openings, a flag associated with each opening and temperature responsive means for first moving one flag for the height of the lower opening .and then moving the second flag into position behind the upper opening.

4. A temperature indicating instrument comprising a disc provided with upper and lower sight openings, a fla associated with the lower opening, a norma ly concealed flag of different color associated with the upper opening and temperature responsive means `for moving said flagsv with respect to said openings said lower flag being 'movable independently of the upper fiag. y

5. A temperature indicating instrument comprising a disc provided with upper and lower sight openings, a flag associated with the lower opening and movable along said opening to indicate temperature, a flag associated with the upper opening and movable' to be visible through said opening to indicate a dangerous temperature and temperature responsive means operative to prolduce movement of the lower flag independently of the upper flag during normal temperaturevariations and to cause movement of the upper flag during abnormal temperature conditions. v

6. A temperature indicatingl instrument comprising a disc provided wit a vertically disposed elongated sight opening and a seci `ond opening above said first opening, a

ide arranged adjacent said openings, a ag on said guide movable along said elonated opening, a flag on said guidemovable into position behind said second opening and temperature responsive means actuated by an increase in temperature to first move the first fiag along said elongated opening and then move the second iiag into view behind said second opening.

7. A temperature indicating instrument comprising a disc provided with a vertically disposed elon ated sight opening and a second opening a ove and spaced from the first opening, a guide arranged adjacent said openings, a liag visible through said elongated opening slida-ble on the lower part opening, means for holding said second iag p adjatent said second opening and temperaturey responsive means for moving said flags with respect to said openings.

8. A temperature indicating instrument comprising a disc rovided with avertically disposed elongated) sight opening and a second opening above and spaced from the lirst opening, a guide arranged adjacent said openings, a flag slidably mounted on said guide and visible through the lower opening, a flag slidably mounted on said guide and normally concealed behind said disc below the second opening, means for supporting said second iag in position below said second opening and tem erature responsive means connected to said rst flag, an increasing temperature servin to cause upward movement of the first ag along said first opening into engagement with `,the second flag and movement' of the second flag into position behind said second opening.

9. A temperature indicating instrument comprising a disc having two sight openings therein, a flag movable along one of said openings to indicate safe temperature conditions, a second flag normally disconnected from the first iag and movable-into view behind'the other opening to indicate dangerous temperature conditions, and temperature responsive means operating during normal temperature conditions for moving the first flag `independently oi the second fiag. 410. A temperature indicating instrument comprising a disc having two vertically disposed spaced apertures therein, a 'flag movable along the lower opening to indicate safe temperature conditions, a flag of different color normally concealed behind said disc and adapted to be moved intoview behind the upper opening to indicate dangerous temperature conditions, and temperature respoisive means connected to said first flag, an increasing tempera/ture serving to move -said first flag vertically into engagement with said second flag and to move said second flag into view behind said second openin A g1. A temperature indicating instrument comprising a temperature responsive device havin an end movable due to temperature variations, a temperature indicating slide, a lever engaging said slide and a link connecting said lever with the movable end of said device. Y

12. A temperature indicating instrument comprising a frame having an opening therein, a disc arran ed in said opening, said disc being provi ed with a vertically disposed sight opening and a second sight openingi disposed above said first openin and spaced therefrom, a guide in sai frame, a red" Hag mounted on said guide said tube to said vsecond Hag whereby and normally concealed behindvsaid disc adan increase in pressure in said tube causes jacent said second opening, a second flag said flag to move vertically along said first slidably mounted on said guide and movable opening, the final upward movement of said 6 longitudinally thereof, a chamber adapted first flag causing the second Hag to be moved 20 to contain a volatile liquid extending below into View behind said second opening.

said frame, a flexible metallic tube in said In testimony whereof, I have hereunto set frame connected to said chamber and adaptmy hand.

ed to be flexed by varying pressures therein 10 and means connecting the flexible end of MORRIS C. WHITE. 

